The present invention relates to a trolley and, more particularly, to a trolley with retractable wheels for carrying large articles such as a golf bag.
Retractable trolleys are known to comprise a pair of vertical bars forming components of a frame, a wheel assembly including a pair of wheels and a pair of linking bars pivotally connected between the pair of vertical bars and the wheel assembly. Each of the wheels is also pivotally linked to the pair of vertical bars or to the frame. A pivotal movement of the linking bars relative to the pair of vertical bars or to the frame will effectuate a change of the wheel between a retracted position and an extended position.
The Applicant's pending U.S. patent application Ser. No. 08/008,576 now U.S. Pat. No. 5,306,027, discloses such a retractable trolley in which an extended or retracted position of the wheels is achieved by manipulating or folding a pair of levers with respect to a pair of vertical bars. When the wheels are in the extended or lifted position, i.e., the levers are at this same in their upward position in line with the vertical bars, hook and pin are utilized to retain this position. To change the wheels to a retracted position, the hook and pin are disengaged from each other and a folding movement of the levers must be performed manually. In this arrangement, there is a potential danger that the hook and pin may be accessed or manipulated by children so that accidental folding down of the levers might occur. In addition to this, a disadvantage inherent to this kind of design, i.e., the requirement of a pivotal or a folding down movement of the levers relative to the vertical bars, is that a sufficiently large space is necessary to permit a folding movement.
In view of the above, there is a need for a retractable trolley which, in operation, does not involve any folding or pivotal movement of certain elements of the trolley relative to other elements thereof. In accordance with the invention, this need is achieved by a retractable trolley which, during a change of positions between a retracted position and a extended position, a sliding movement is exercised. Moreover, in the present invention, this sliding movement is performed under minimal human intervention and can be controlled in a safe way.